package PC;

/**
 * @author zjq
 * @date 2020/3/25 15:57
 */
//生产者与消费者

/**
 * 线程之间的通信问题：生产者和消费者
 * 线程 A B 操作同一个变量 num
 * A num+1
 * B num-1
 */
public class pc {
    public static void main(String[] args) {
        Data data = new Data();
        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                try {
                    data.increment();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }, "A").start();
        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                try {
                    data.decrement();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }, "B").start();
        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                try {
                    data.increment();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }, "C").start();
        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                try {
                    data.decrement();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }, "D").start();
    }
}

//判断等待 业务 通知
class Data {//资源类
    private int num = 0;

    //+1
    public synchronized void increment() throws InterruptedException {
        while (num != 0) {
            //等待
            this.wait();
        }
        num++;//通知线程+1完毕
        System.out.println(Thread.currentThread().getName() + "----->" + num);
        this.notifyAll();
    }

    //-1
    public synchronized void decrement() throws InterruptedException {
        while (num == 0) {
            //等待
            this.wait();
        }
        num--;//通知线程-1完毕
        System.out.println(Thread.currentThread().getName() + "----->" + num);
        this.notifyAll();
    }

}
